Regarding security and access, OS is still not that good unfortunately. V3 api should have a better access control, but it's still far behind Amazon's ACLs unfortunately.

Do you really want to deal with all the hardware yourself though? Juggling failing disks, dealing with system upgrades, managing edge of the network, debugging strange one-off issues that sometimes require firmware updates, backup power systems, etc. ? Any cloud provider is better/cheaper unless you need multiple racks and hire people to manage them.